“An earlier version of this article included material borrowed and duplicated, without attribution, from Environmental Health Perspectives, a monthly scientific journal. In that earlier version, four sentences were copied in whole or in substantial part from ‘Progress and Pollution: Port Cities Prepare for the Panama Canal Expansion,’ published on Dec. 3 and written by Andrea Hricko, a professor of preventive medicine at the Keck School of Medicine of the University of Southern California.

“It is The Post’s policy that the use of material from other newspapers or sources must be properly attributed. The Post apologizes to Andrea Hricko, to Environmental Health Perspectives, and to its readers for this serious lapse.”

Editor Marty Baron sent a written apology to Hriko, a professor at Keck School for Medicine of the University of Southern California saying, “This represented a serious violation of our ethics standards. It was a disservice to you, and it breaks faith with our readers. You have our deepest apology, and you have our assurance that we are taking this matter very seriously.” That written apology was given to POLITICO.

The reporter also apologized saying that it was “an inadvertent and sloppy mistake.”

“The Post will be taking severe and appropriate action with regard to Mr. Booth,” according to statement from the Washington Post communications director Kristine Coratti, but the statement did not provide specifics.

Patrick Pexton, the Washington Post ombudsman, tweeted after the story was updated, “‘The Post will be taking severe and appropriate action with regard to Mr. Booth.’ Newsroom sources say he will not, however, be fired.”